1. Field of the Invention
The invention relates to an applicator unit for a liquid or semi-liquid product, such as a cosmetic product. The invention concerns more particularly, but not exclusively, an applicator unit of the eyeliner type. Other applications in the cosmetic field may be envisaged such as, in particular, the application of hair products, a liquid serum, nail varnish, eyeshadow, liquid lip rouge, mascara, etc. The invention also applies to fields other than cosmetics. Glues may be mentioned by way of example.
2. Discussion of the Background
An applicator unit of the above mentioned kind conventionally comprises a bottle provided with a threaded neck and intended to contain a liquid or semi-liquid product, a cap closing the bottle by being screwed onto the neck and an applicator disposed at the end of a stem joined to the cap. This applicator generally also includes means for wiping the applicator and wiping the stem.
FR-A-2 470 066 relates to a device of the above mentioned type, into the neck whereof there is placed a molded part having lips forming scrapers disposed on top of one another and having a triangular cross-section. Such a scraper makes it possible not only to wipe the stem, but also to wipe the applicator, which in this case is a brush.
EP-A-0 640 302 describes a mascara applicator comprising a wiper element of an annular shape and provided with a plurality of projections extending radially inward of the reservoir, intended to scrape off the excess of the product on the applicator when it is being withdrawn from the reservoir.
French Patent Application 95/02197, filed in the name L'Oreal on Feb. 24, 1995, describes an applicator unit for a liquid or pasty product comprising a diabolo-shaped wiper made of a deformable elastic material traversed by the applicator during its extraction from the reservoir. The wiper is capable of wiping the stem and of increasing its passage cross-section to allow the passing of an applicator element which has a cross-section greater than that of the stem.
FR-A-2 504 788 describes a make-up unit comprising a brush penetrating inside the reservoir through a flexible rubber body shaped as a glove finger whose pierced bottom forms a wiper lip which is denticulated so that its teeth are capable of penetrating into the grooves of the brush between two adjacent rows of bristles, so as to exert a wiping action inside the grooves.
Other wiper devices are, moreover, described in the FR-A-2 515 941, FR-A-2 579 430 or FR-A-2 580 479.
The wiping systems described in these documents are mechanical wiping elements wherein the wiping of the stem and/or of the applicator is effected by contact or friction between the wiper and the element to be wiped. However, these systems produce results which are sometimes inadequate, in particular when the applicator has a diameter substantially smaller than the diameter of the stem carrying it. This is, in particular, the case with certain applicators carried by a stem whose diameter may vary between 2.5 mm and 3 mm, the applicator taking the form of a tapered element whose largest diameter is of the order of 2 mm and whose tip has a diameter of the order of 0.2 mm. Thus, when such an applicator passes into a wiper element of the type described above, proper wiping of the stem is obtained. On the other hand, the free end of the applicator is not wiped and retains a larger or smaller drop of the product, such a drop subsequently renders difficult the application of the product which results in poor product quality.
Moreover, in the known devices, where the wiping is obtained by an elastically deformable annular element having a slit hole, the quality deteriorates in the course of use, because the material loses its elasticity. Moreover, when it is introduced into the slit hole the applicator is subjected to stresses which may irreversibly damage it.
Finally, in the glove finger-type device described in the above mentioned FR-A-2 504 788, the product entering the glove finger is too abundant to ensure a proper charging of the applicator, to the detriment of the fineness of the point.
Thus, all known devices are of two types. In a first type, the wiper is dimensioned to the diameter of the applicator, so as to wipe the applicator by friction (of the type of a wiper with a slit hole). In this case, because of the small diameter of the slit hole in its rest position, the applicator is subjected to high mechanical stresses, in particular when it is introduced, which may irreversibly damage it. Moreover, the wiper with a slit hole loses its elasticity in the course of use, which inevitably entails a deterioration in the quality of the wiping. With a second type, the diameter is dimensioned to the diameter of the stem, in which case the applicator passes through the wiper without being correctly wiped.